Intended for teachers of deaf-blind and severely handicapped students as well as for resource or itinerant teachers in the area of vision who have recently begun to serve low functioning students, the manual provides information on vision and on vision assessment. The manual serves three functions. It: (1) prepares teachers for participation in interdisciplinary or transdisciplinary teams; (2) provides visual efficiency assessment procedures, and (3) provides guidelines for instructional procedures used to establish functional vision use in the classroom. Following a review of the structure and function of the eye, general assessment considerations are examined: gross measures of vision, ocular coordination, peripheral vision, tracking and gaze shift, and refractive errors and acuity measures. A decision model is then presented to chart the progression of the vision assessment. A final section presents guidelines for functional vision programming based on application of operant principles in the context of data based instruction. Six specific steps are outlined: (1) selecting vision objectives, (2) selecting a paired skill, (3) defining critical visual moments, (4) teaching strategies and error correction procedures, (5) teaching the paired skill, and (6) monitoring data. Data sheets are appended along with a discussion of medications and their effects on vision. (CL)